Abrading or sanding machine and method



March 26, 1940. o s

' ABRADING 0R SANDING MACHINE AND METHOD Filed March 15, 1938 4 Sheets-Sheet 1 & INVENTOR.

ATTORNEY).

March 26, 1940.

I N. POTASH ABRADING 0R SANDING MACHINE AND METHOD Filed March 15, 1938 4 Sheets-Sheet 2 INVENTOR.

ATTORNEYS.

March 26, 1940. r po-r s 2,195,340

' ABRADING 0R SANDING MACHINE AND METHOD Filed March 15, 1938 4 Sheets-Sheet s INVENTOR.

. i744, WI/LZ BY I I ATTORNEY-5'.

March 26, 1940. v

r N. POTASH ABRADING on SANDING MACHINE AND Mnwnon Filed March 15, 1958 4 Sheets-Sheet 4 INVENTOR. a

A TTORNEYJI Patented Mar. 26, 1940 i uNiTED STATES ABRADING R SANQDIING MACHINE AND.- METHOD Norman'Potash, Baltimore, Md. Application March 15, 1938, Serial No. 196,058

6 Claims.

This invention relates to a method of abrading, sandpapering or sanding, and to a machine for the same, for use in the woodworking arts.

Particular objects and advantages of the invention will be hereinafter set forth.

In the accompanying drawingswhich represent what is at present believed to be the preferred embodiment of the invention:

Fig. 1 isa top plan View; 1 Fig. 2 is a longitudinal section on the line 2- of Fig, 1, with certain parts shown inelevation, and other parts omitted; t

Fig. 3 is a fragmentary perspective View of one of p the two table sections and part of the supporting frame;

Fig. 4 is a sectional view, on a larger scale, of part of the mechanism shown in section under the bracket 4--4 in Fig. 2;

Fig. 5 is a diagrammatical top view showing the reciprocating abrading action of the machine;

Fig. 6 is a perspective detail view of parts of one of the reciprocating carriers forthe sanding shoes or plates;

Fig. '7 is a perspective detail view of parts of Fig. 8 is a perspectivedetail view of said slide Fig. 9 is a perspective detail view of 'a sanding shoe or plate adapted to be mounted on and to constitute part of one of the carriers, other parts of which are shown in Fig. 6; Fig. 10 is a fragmentary detail view in elevation of a modified form of rubber belt for the sanding shoes;

Fig. 11 is a vertical sectional view on line I l-l I of Fig. 10;

Fig, 12 is a vertical sectional view on the line l2--l2 of Fig. l, with some parts shown in elevation;

Fig. 13 is a detail perspective view of the driving shaft coupling; v

Fig. 14 is a fragmentary view in side elevation of one of the sand belt tensioning or take-up devices; and

.Figs. 15 and 16 are detail perspective views an adjustable guide for material to be fed into two tables (see Fig, 12).

Reinforcing ribs on The bars 20 and 2| are supported between 24 is fixed to member 22 by screws 21 and 28.

Table 24', howeveigis slidable on the bars 20 and 2! and may be moved. thereon relative to table 24 by operation of the crank connection 30.

Fig. 2 illustrates the principal shaft and ear connections of the driving mechanism. Power from a source. not shown is transmitted, as by belt 5, to pulley 3| inounted on shaft 32. Shaft 32 is journalled in bearings 33 and34'mounted be neath table 24, and passes through suitable openings in the before mentioned ribs of said table. Shaft 32' beneath table 24 is journalled in bearings 33 and 34' for rotationponthe same axis with shaft 32; and the. two shaftsare'connected by a coupling shown 'in detail in Fig. 13, and comprising a tongue 36 formed on shaft32', and the 40, and is'similarly journalled' on the bearings of supports 4i" and 42' and driven counter to shaft 32 by connecting gears 43' and 44. I

Two reciprocatory carriers for bands or; belts having surfaces of sanding or abrasive material are driven from the shafts and 4| respectively.

The inner or opposing ends of said shafts 40 and 40' carry blocks 99 and 99 on which are formed theeccentric end portions or crankpins .45 and 45 which actuates the opposed reciprocating carriers respectively. as Willbe further described presently. The outer end of shaft 40 carries a bevel'gear 46 which meshes with bevel ear 41 mounted on verticalshaft 48. The lower end of shaft 48 carries a driving sprocket 49, and from said sprocket a sprocket-chain 5ll (see cutaway and dotted portions'in Fig. 1) forms the. driving means for all sand belt driving pulleys and slat feeding rollers and rotary brushes carr1ed.by table 24. Similarly, shaft 40f on table .24 carries a bevel gearw" at its outer end, which gear meshes withbevel gear 41' on'vertical shaft 48' for operating sprocket 49'. Sprocket 49' drives the belt driving pulleys and slat feeding rollers and rotary brushes on table 24' by a chain 50, which operates one. higher plane (due to the shorter shafts employed) than. chain 50 to avoid interference at the opposing edges of the Two abradingor sanding bands or endless belts and 55 having opposed portions where said bands or belts pass over thereciprocating carriers respectively and engage the interposed work to be abraded, are mounted and driven on the two tables 24 and 24' respectively. Starting from the point at which it leaves the plate 10 of the left hand carrier (Figs. 1 and 5), belt 55 travels toward the left, againstythe take-up or tensioning carriers when the latter are in operation. From plates.

roller 5! and around the idler pulley 52. Four of these tensioning rollers may be seen in Fig. 1, numbered 5!, Ella, 5i?) and 5E0, supported on the axles of the idler pulleys 52, 52a, 52b, 52c. Fig. 14 is a detail view of tensioning roller 5k: and idler pulley 52c. This idler pulley revolves on axle 53. A pair of arms 5i and 53 extending from axle 53 support the axle fiowhich carries roller 5ic. Spring arm 59 is fixed to the top of axle 53 by abolt 86 in Fig. 14, and bears against axle 56 forcing roller alcagainstsand belt 55'. By loosening set screw and turning axle 53 the pressure of the spring arm against axle 56 may be adjusted, and the flapping ofthe sand belt due to the reciprocating movement of the right hand carrier comprising plate or shoe l0, and also any undesired slack, maybe taken up. The sanding or abrading bands or belts should at all times be maintained with slack at the minimumto prevent slippage of the belts on the tensioning roller '52, the belt passes around the large driving pulleys (i0 and BI (Fig, 1). Pulley 6i and its driving connection are shown in Fig. 12, wherein pulley (H is mounted on a vertical shaft 62 in a tubular housing 64 extending through table 25. Sprocket "63 at the lower end of shaft 62 is driven by chain at.

From pulley 61 the sanding belt 55 passes prising plates or shoes in and/Iii, over which pass the belts 55 and 55' respectively, are mounted on the opposed edges of the tables 24 and 24, as shown in Figs. 1. 2 and 4, in which corresponding parts have the same reference numerals, those on table 24'being primed. Figs. 6 through 11 are detail views of the reciprocatory carrier which comprises the plate or shoe 10' and its supporting parts, the description of which may be applied to thoseof the corresponding left-hand reciprocatory carrier which comprises the plateor shoe ill on the table 26.

In'Fig. 6, the U-shaped support 12' has a flat base adapted to be'bolted toltable 2-4. A-pair of horizontally disposedparallelbars l5"-and 16' are clamped in semi-circular grooves across the forward faces of'the upright arms 13 and 74 by the clamping members 11' and 1-8 which'latter.

are also provided with semi-circular grooves. The reciprocating frame is preferably of aluminum and is slidably mounted-on the'bars 'l5'iand T6 for lateral movement. Suitable bushings 8 i and 82 are provided in the bar-openings of the frame BU and oil-cups 83 and 84 lubricate bars 15 and '16 respectively. In the center of the frame 80 there is a rectangularaperture 85' having bearing plates-86 and 81 on the side walls thereof and oil-cups 88 and 89 for lubricating said In Fig. 7 the block shaped counterbalance 99 is shown with the crank pin 45 formed on the upper part of its forward face, and is mounted on-the end of shaft 40' by an oil center boring, and secured by two screws I02 and N33.

The larger and heavier portion N14 is disposed at height for feeding.

the slat is automatic.

the opposite side of the shaft from the crank pin to counteract the centrifugal thrust of the latter. Slide block 9!, shown in detail in Fig. 8, is carried by crank pin 45' and retained thereon by cap 92' screwed to the end of the pin; These parts are shown in assembled position in Fig. 4. Slide-block 9| fits snugly to the bearing plates 86 and 81 on side walls of the aperture 85 and when crank pin 45' is rotated, slides in a vertical paththerein while imparting to frame 80 the lateral movement of the crank pin.

Fig. 9 is a perspective detail of the plate 10' constructed of sheet metal, preferably aluminum. Plate 1-0 has two rearwardly bent upper and lower flanges 93 and 94 adapted to fitover the top a and bottom respectively of frame 80, and are attached thereto by four screws two of which, 95

and 96', for the top, are shown in Fig. -9. At each vertical edge of the plate 10 are mounted the rollers 91' and 98' (preferably of aluminum) rotatable on vertical axles extending between the flanges 93' and 94. Trained around these rollers and across the face of plate 10' is the endless belt H10, preferably of a resilient material such as sponge rubber having a flexible backing 4535 of canvas or like material. Additional resiliency may be obtained by cutting or forming a tread in the rubber face of the belt, such as shown in the modified belt 10! of Figs. 10 and ll. The belt is movable around the rollers 91 and .98 and plate 10' in the same direction withthesanding belt 55 when the machine is in operation.

In Fig. l a slat or board 1| is'shown being fed into the machine between the two opposed sanding belts. machine in said figure, the slat H rests against an L-shaped adjustable guide H0 mounted at the edge of table 24 (see also Figs. 15 and 16).

The base of the guide is fixed to the table by a pair of screws HI and H2 passing through slots H3 and H4 having sufficient. length to allow lateral adjustment of the guide for different thicknesses of slats or boards. The upright portion of the guide hastwo vertical slots H5 and HE. A bar H1 is clamped to the face of the Beginning at the lower edge of the From guide Ill! theslat passes between two positively driven feed rollers H8 and H8, from which point the feeding of The rollers 1 t8 and H8 are preferably of solid rubber, and are located respectively-at-the edges of tables '24%and.2l in a similarly mounted on shaft H19 .in housing ai'lil'.

Sprocket I2! is driven by chain 59.

The slat 1| next passes betweenthe portions of sanding belts 55 and55 which pass over the reciprocatory carriers comprising shoes 10 and 10 respectively, and is sanded. lnl Fi g-il the movements. of the parts are diagrammatically represented. It will be noted that the carriers comprising the shoes 10 and H and the portions of the sanding belts passing thereov-er reciprocate inopposite directions; when one shoe is moving in the direction of feed-of theslat Myths other is moving in'the opposite direction, and vice versa. This arrangement gives the best sanding results'and also prevents the slat from i Jill being pulled in one direction or the other and interfering with the feed. From between the shoes the slat "II passes between a pair of rotary cleaning brushes I22 and I22 (Figs. 1 and 5)' which are mounted on tables 24 and 24', and rotated opposite to'the direction of travel of the slat. The supports and driving sprockets for the brushes are not shown in detail in the drawings,

but correspond generally to those previously described for the feed rollers H8 and H8. The sprockets connecting the brushes with chains 50 and 58' should, however, be smaller than those for the feed rollers, to provide comparatively greater speed of rotation in the brushing action.

The brushes not only clean the slats after they are sanded, but, by reason of their location closely adjacent the shoes, also clean the sand belts as .well. The belts are alternately pressed against the brushes at the end of. the stroke of theshoes toward said brushes, as shown in Fig. 5. From the cleaning brushes I22, I22, slat 'II passes between positively driyen feed rollers I23, I23 similar to and driven in the same manner as that previously mentioned for feed rollers H8, H8.

The chains 50 and 50' after passing around the sprockets for rollers I23, I23 pass over the idler sprockets I24 and I24 on axles depending from .the tables 24 and 24 respectively. The courses cating strokes of shoes, 40 per second; length of without the need of separate regulation.

of the chains are shown in dotted lines in Fig. 1,

and require no added description.

The invention may be. constructed to any dee sired proportions according to the requirements of the particular materials to be sanded. The machine shown in the drawings is especially adapted for sanding materials ranging from thick boards to very thin strips of wood, such as slats to be used in Venetian blinds.

In such a machine thefollowing dimensions and speeds are suggested as being preferable; the length of the plates or shoes 10, I0, 8 inches; speed of sand belts 55, 55' and of slat feeding parts, 8 inches per second; number of reciprosaid strokes, 1%; inches; speed of brushes I22 and I22, 40 inches per second. A machine constructed and adjusted accordingly will. deliver 40 sanding strokes to every point on a slat.

As thus appears from the foregoing description, the machine is capable of sanding both sides of slats or boards simultaneously and by a very ad.- vantageous reciprocating rubbing action consisting of a large number of short, quick strokes. During this action the feeding and brushing of the slat is continuous and automatic. Long lengths of sanding belt are provided and these are continuously moved and cleaned to present a fresh sanding surface to the reciprocating shoes. The feeding, sanding, and brushing parts may be readily adjusted by a single adjusting means to surfaces of saidbelts a reciprocating sanding action independent of said movement. The method mayalso includebrushing or cleansing said slat after it is sanded, and cleansing the belts.

. What is claimed is: I

1. An abrading or sanding machine including, in combination, a pair of endless abrading belts, means for supporting said belts with portions of their faces in opposed relation, means :for adsame between a pair of continuously moving opposed sanding belts; in imparting to the opposed.

vancing'said belts, means for feeding work material between said opposed'portions of thefaces,

and common means for simultaneously brushing said material and said belts after the sanding operation.

2. An abrading or sanding machine including, in combination, a pair of opposed plates or shoes, a pair of endless abrading belts trained over the opposed surfaces of said shoes, means for advancing said belts, driving means for imparting to said shoes and said belts a reciprocating abrading motion, and synchronizing means associated with said driving means for maintaining the said reciprocating abrading motion of'said shoes and said belts in directions opposite to each other.

3. An abrading or sanding machine including, in combination, supporting means, a pair of table sections mounted on said means with an edge of one section adjacent an edge of the other section, a pair of opposed plates or shoes mounted on said sections near said. edges respectively, a pair of endless abrading belts mounted on pulleys carried by said sections respectively and trained over. the opposed faces of said shoes, feeding means comprising pairs of feed rollers, brushing means comprising a pair of rotary brushes; chain driving means for rotating said belts, said feeding, and said brushing means; and crank driving means for imparting to said shoes and said belts a reciprocating abrading motion. ,1

4. An abrading or sanding machine including,

in combination, a pair of opposed endless abrading belts, means for supporting the same with portions of their faces in opposed relation, means for advancing said belts, means for imparting to said opposed portions a reciprocatory abrading motion, means for feeding work material between said opposed portions; a pair of rotary cleaning brushes each disposed for contacting a belt and a side of the material after the abrading operation, andmeans for-driving said brushes in a direction opposite the direction of feed of the material and in a common direction with the direction of driveof the belts whereby said belts are cleaned by a picking action. I I

5. An abrading or sanding machine according to claim 4, wherein the rotary cleaning brushes are brought into intermittent contact with the belts by the reciprocatory abrading motion of the latter. I i

6. An abrading or sanding machine including, in combinatioma pair of opposed plates or shoes, a pair of endless belts trained over the opposed surfaces of said shoes, means for advancing said belts, and means connecting said shoes with a single source of power for imparting to each shoe and belt a reciprocating abrading motion in a direction opposite to that of the other shoe and belt. 7 Y I NORMAN POTASH. 

